Abstract:
:Formamide-induced detubulation of rat ventricular myocytes was used to investigate the functional distribution of the Na/Ca exchanger (NCX) and Na/K-ATPase between the t-tubules and external sarcolemma. Detubulation resulted in a 32% decrease in cell capacitance, whereas cell volume was unchanged. Thus, the surface-to-volume ratio was used to assess the success of detubulation. NCX current (I(NCX)) and Na/K pump current (I(pump)) were recorded using whole-cell patch clamp, as Cd-sensitive and K-activated currents, respectively. Both inward and outward I(NCX) density was significantly reduced by approximately 40% in detubulated cells. I(NCX) density at 0 mV decreased from 0.19 +/- 0.03 to 0.10 +/- 0.03 pA/pF upon detubulation. I(pump) density was also lower in detubulated myocytes over the range of voltages (-50 to +100 mV) and internal [Na] ([Na](i)) investigated (7-22 mM). At [Na](i) = 10 mM and -20 mV, I(pump) density was reduced by 39% in detubulated myocytes (0.28 +/- 0.02 vs. 0.17 +/- 0.03 pA/pF), but the apparent K(m) for [Na](i) was unchanged (16.9 +/- 0.4 vs. 17.0 +/- 0.3 mM). These results indicate that although thet-tubules represent only approximately 32% of the total sarcolemma, they contribute approximately 60% to the total I(NCX) and I(pump). Thus, the functional density of NCX and Na/K pump in the t-tubules is 3-3.5-fold higher than in the external sarcolemma.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Despa S,Brette F,Orchard CH,Bers DMdoi
10.1016/S0006-3495(03)74758-4subject
Has Abstractpub_date
2003-11-01 00:00:00pages
3388-96issue
5eissn
0006-3495issn
1542-0086pii
S0006-3495(03)74758-4journal_volume
85pub_type
杂志文章abstract::Hepatitis C is a major worldwide disease and health hazard, affecting ∼3% of the world population. The p7 protein of hepatitis C virus (HCV) is an intracellular ion channel and pH regulator that is involved in the viral replication cycle. It is targeted by various classical ion channel blockers. Here, we generated p7 ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2016.04.018
更新日期:2016-06-07 00:00:00
abstract::Photosystem II catalyzes photosynthetic water oxidation in plants, green algae, and cyanobacteria. The manganese-containing active site cycles through a series of five oxidation states, S(n), where n refers to the number of oxidizing equivalents stored. In this report, reaction-induced Fourier transform infrared and e...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74680-3
更新日期:2003-10-01 00:00:00
abstract::Lipid mixing between vesicles functionalized with SNAREs and the cytosolic C2AB domain of synaptotagmin-1 recapitulates the basic Ca(2+) dependence of neuronal exocytosis. However, in the conventional ensemble lipid mixing assays it is not possible to discriminate whether Ca(2+) accelerates the docking or the fusion o...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2010.12.3730
更新日期:2011-02-16 00:00:00
abstract::The dynamics of proton transfer between the surface of purple membrane and the aqueous bulk have recently been investigated by the Laser Induced Proton Pulse Method. Following a Delta-function release of protons to the bulk, the system was seen to regain its state of equilibrium within a few hundreds of microseconds. ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74887-5
更新日期:2003-01-01 00:00:00
abstract::The folding pathway of the small α/β protein GB1 has been extensively studied during the past two decades using both theoretical and experimental approaches. These studies provided a consensus view that the protein folds in a two-state manner. Here, we reassessed the folding of GB1, both by experiments and simulations...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.09.013
更新日期:2011-10-19 00:00:00
abstract::A continuum model is provided of the free energy terms that contribute to the molecular association of ricin A-chain (RTA) with the rRNA substrate and several small ligands. The model for RTA interactions with the RNA was taken from a previously proposed complex containing a 29-mer oligonucleotide hairpin (. Proteins ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(99)77175-4
更新日期:1999-01-01 00:00:00
abstract::The thylakoid membrane has a unique lipid composition, consisting mostly of galactolipids. These thylakoid lipids have important roles in photosynthesis. Here, we investigate to what extent these lipids bind specifically to the Photosystem II complex. To this end, we performed coarse-grain MD simulations of the Photos...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2017.09.039
更新日期:2017-12-19 00:00:00
abstract::Halorhodopsin (HR), the light-driven chloride transport pigment of Halobacterium halobium, was bleached and reconstituted with retinal analogues with the pi electron system interrupted at different locations (dihydroretinals). The absorption maxima of the artificial pigments formed with the dihydroretinals are found t...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)83080-7
更新日期:1988-02-01 00:00:00
abstract::The efficiency of various patterns of pulsatile stimulation is determined in a model in which a receptor becomes desensitized in the presence of its stimulatory ligand. The effect of stochastic or chaotic changes in the duration and/or interval between successive pulses in a series of square-wave stimuli is investigat...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(92)81824-6
更新日期:1992-01-01 00:00:00
abstract::To probe the complexity of the cell membrane organization and dynamics, it is important to obtain simple physical observables from experiments on live cells. Here we show that fluorescence correlation spectroscopy (FCS) measurements at different spatial scales enable distinguishing between different submicron confinem...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.067959
更新日期:2005-12-01 00:00:00
abstract::Here, we report the first direct observation of Van der Waals' attraction between biomembrane capsules using measurements of the free energy reduction per unit area of membrane-membrane contact formation. In these studies, the membrane capsules were reconstituted neutral (egg phosphatidylcholine) lipid bilayers of gia...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(84)84039-4
更新日期:1984-09-01 00:00:00
abstract::The influence of patch electrode glass composition on macroscopic IV relations in inside-out patches of the cGMP-activated ion channel from rod photoreceptors was examined for a soda lime glass, a Kovar sealing glass, a borosilicate glass, and several soft lead glasses. In several glasses the shape or magnitude of the...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(88)83091-1
更新日期:1988-02-01 00:00:00
abstract::Prion diseases are infectious fatal neurodegenerative diseases including Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. The misfolding and conversion of cellular PrP in such mammals into pathogenic PrP is believed to be the key procedure. Rabbits are among the few mammalian species...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.08.018
更新日期:2011-09-21 00:00:00
abstract::Widely disparate viruses enter the host cell through an endocytic pathway and travel the cytoplasm inside an endosome. For the viral genetic material to be delivered into the cytoplasm, these viruses have to escape the endosomal compartment, an event triggered by the conformational changes of viral endosomolytic prote...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.12.037
更新日期:2012-03-07 00:00:00
abstract::Clostridium difficile (C. diff) is one of the most common and most severe hospital-acquired infections; its consequences range from lengthened hospital stay to outright lethality. C. diff causes cellular damage through the action of two large toxins TcdA and TcdB. Recently, there has been increased effort toward devel...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.05.031
更新日期:2013-07-16 00:00:00
abstract::A recent analysis of the normal modes of vibration of a ring formed by bringing together and sealing, with or without the addition of twist, the ends of rods that are straight when stress free is taken as the basis for a theory of the statistical thermodynamics of a canonical ensemble of DNA minicircles with specified...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77962-7
更新日期:1998-05-01 00:00:00
abstract::We developed a multicellular model characterized by a high degree of heterogeneity to investigate possible mechanisms that underlie circadian network synchronization and rhythmicity in the suprachiasmatic nucleus (SCN). We populated a two-dimensional grid with 400 model neurons coupled via γ-aminobutyric acid (GABA) a...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2011.04.051
更新日期:2011-07-06 00:00:00
abstract::In this article we present a study of a new class of surfactants denoted as PEG1500-12-acyloxystearates, which have potential use as pharmaceutical solubilizers. These amphiphilic molecules present interesting properties with regard to cell damage effects. PEG1500-12-acyloxystearates with C(14) to C(16) acyloxy chains...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.107.109900
更新日期:2007-12-15 00:00:00
abstract::We investigate the isometric transient response of muscle using a quantitative stochastic model of the actomyosin cycle based on the swinging lever-arm hypothesis. We first consider a single pair of filaments, and show that when values of parameters such as the lever-arm displacement and the cross-bridge elasticity ar...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(03)74522-6
更新日期:2003-08-01 00:00:00
abstract::The elastic rigidity (stiffness) of impaled motionless bull sperm flagella has been determined by a manipulatory technique which permitted direct analytical treatment of the experimental system. The effects of external ATP and ADP were measured. It was found that ATP acts as a plasticizing agent, while ADP does not. T...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(73)85997-1
更新日期:1973-05-01 00:00:00
abstract::Interactions between millimeter waves (MMWs) and biological systems have received increasing attention due to the growing use of MMW radiation in technologies ranging from experimental medical devices to telecommunications and airport security. Studies have shown that MMW exposure alters cellular function, especially ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2013.05.014
更新日期:2013-06-18 00:00:00
abstract::The photocycle of the photophobic receptor sensory rhodopsin II from N. pharaonis was analyzed by varying measuring wavelengths, temperature, and pH, and by exchanging H2O with D2O. The data can be satisfactorily modeled by eight exponents over the whole range of modified parameters. The kinetic data support a model s...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(98)77588-5
更新日期:1998-08-01 00:00:00
abstract::mRNAs are involved in complicated supramolecular complexes with human 40S and 80S ribosomes responsible for the protein synthesis. In this work, a derivative of nonaribonucleotide pUUCGUAAAA with nitroxide spin labels attached to the 5'-phosphate and to the C8 atom of the adenosine in sixth position (mRNA analog) was ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/j.bpj.2015.10.042
更新日期:2015-12-15 00:00:00
abstract::Fourier-transform infrared spectroscopy is a method of choice for the experimental determination of protein secondary structure. Numerous approaches have been developed during the past 15 years. A critical parameter that has not been taken into account systematically is the selection of the wavenumbers used for buildi...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1529/biophysj.105.072017
更新日期:2006-04-15 00:00:00
abstract::The partition coefficients (K(P)) of a series of single-chain and double-chain fluorescent amphiphiles, between solid ordered (P(beta') and L(beta)) and liquid disordered (L(alpha) of the type l(d)) lipid phases coexisting in the same lipid bilayer, was studied using steady-state fluorescence emission anisotropy. The ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(00)76840-8
更新日期:2000-06-01 00:00:00
abstract::Optical potentiometric indicators have been used to monitor the transmembrane electrical potential (Em) of many cells and organelles. A better understanding of the mechanisms of dye response is needed for the design of dyes with improved responses and for unambiguous interpretation of experimental results. This paper ...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(90)82603-5
更新日期:1990-04-01 00:00:00
abstract::Proton permeation rates across membranes of a synthetic branch-chained glycolipid, 1,3-di-O-phytanyl-2-O-(beta-D-maltotriosyl)glycerol (Mal3(Phyt)2) as well as a branch-chained phospholipid, diphytanoylphosphatidylcholine (DPhPC) were lower than those of straight-chained lipids such as egg yolk phosphatidylcholine (EP...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(01)75970-X
更新日期:2001-12-01 00:00:00
abstract::Connectin (titin) is a large filamentous protein (single peptide) with a molecular mass of approximately 3 MDa, contour length approximately 900 nm, and diameter approximately 4 nm, and resides in striated muscle. Connectin links the thick filaments to the Z-lines in a sarcomere and produces a passive elastic force wh...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(93)81261-X
更新日期:1993-11-01 00:00:00
abstract::It was shown previously that a significant fraction of the myosin crossbridges is attached to actin in the skinned rabbit psoas fibers under relaxed conditions at low ionic strength and low temperature (Brenner, B., M. Schoenberg, J. M. Chalovich, L. E. Greene, and E. Eisenberg. 1982. Proc. Natl. Acad. Sci. USA. 79:72...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(89)82838-3
更新日期:1989-03-01 00:00:00
abstract::Detection algorithms are widely used for the analysis of single-channel data because they remove the background noise from the measured current signal and reconstruct the noise-free time series. Standard detection algorithms assume channels switching only between zero and full conductance. Many types of channels, howe...
journal_title:Biophysical journal
pub_type: 杂志文章
doi:10.1016/S0006-3495(94)80614-9
更新日期:1994-10-01 00:00:00